added more input validation
added more input validation

scottviteri/drake,astrorog/drake,thientu/drake,billhoffman/drake,tkoolen/drake,sheim/drake,edowson/drake,edowson/drake,scottviteri/drake,scottviteri/drake,hanssusilo/drake,hanssusilo/drake,psiorx/drake,hanssusilo/drake,edowson/drake,thientu/drake,psiorx/drake,thientu/drake,crogers3/drake,hanssusilo/drake,billhoffman/drake,billhoffman/drake,tkoolen/drake,psiorx/drake,crogers3/drake,sheim/drake,tkoolen/drake,thientu/drake,psiorx/drake,astrorog/drake,sheim/drake,astrorog/drake,sheim/drake,psiorx/drake,edowson/drake,scottviteri/drake,psiorx/drake,edowson/drake,astrorog/drake,billhoffman/drake,astrorog/drake,crogers3/drake,scottviteri/drake,sheim/drake,sheim/drake,astrorog/drake,tkoolen/drake,edowson/drake,scottviteri/drake,sheim/drake,thientu/drake,hanssusilo/drake,thientu/drake,psiorx/drake,psiorx/drake,billhoffman/drake,crogers3/drake,tkoolen/drake,crogers3/drake,billhoffman/drake,hanssusilo/drake,sheim/drake,hanssusilo/drake,hanssusilo/drake,astrorog/drake,crogers3/drake,tkoolen/drake,edowson/drake,billhoffman/drake,scottviteri/drake,tkoolen/drake,crogers3/drake,thientu/drake,billhoffman/drake,crogers3/drake,edowson/drake